Tangential cutting inserts are known from the prior art. An example can be found in DE 10 2007 022 536 A1. The tangential cutting insert has two opposite, similar and substantially square bottom surfaces which are rotated with respect to one another. Formed along the outer peripheries of the bottom surfaces are four similar side surfaces, wherein in each case one main lip is formed at the transition from each side surface to the two bottom surfaces. Formed at the transition between adjacent side surfaces are secondary lips which merge into the respective main lip via a corner radius. A total of eight lips are formed which are available for cutting a material to be machined.
The geometry of the side surfaces is comparatively complex. One reason for this is that each side surface extends between the outer peripheries, rotated relative to one another, of the bottom surfaces. In addition, chip-forming geometries are realized on each side surface, the shape of the chips which are removed with the two lips of a side surface being influenced by said chip-forming geometries. The complex shape of the side surfaces makes it difficult to arrange the tangential cutting insert in the receptacle of the tool holder such that the forces that arise during cutting are introduced into the tool holder in the desired manner.
US 20100254776 A1 discloses a tangential cutting insert which has two frustoconical protrusions on each side surface, said frustoconical protrusions serving to support the tangential cutting insert in a receptacle of a tool holder. In addition to the fact that the protrusions complicate the production of the tangential cutting insert, they impair the chip flow on the side surfaces which represent the rake faces of the cutting insert.